Method of making separable fasteners



Nov. 9', 1937. su pg c 2,098,651

METHOD OF MAKING SEPARABLE FASTENERS Original Filed Aug. 8, 1933 JNVENmk; Gideon Sundbac BY v W 1+- Agmwsys. 7

Patented Nov. 9, 1937 METHOD OF MAKING SEPARABLE FASTENERS.

Gideon Sundback, Mcadville, Pa., assignorto Hookless Fastener Company, Meadville, Pa., a corporation of Pennsylvania Application August 8,

1933, Serial No. 684,237

Renewed August 22, 1935 8 Claims.

My invention relates to the manufacture of separable interlocking fasteners and its principal object is to provide an inexpensive and practical method of'making such fasteners.

My invention isparticularly suitable for manufacture of separable interlocking fasteners of the type having interlocking members of non-metallic material. Examples of suitable materials forthis purpose are cellulosic products such as pyralin, and phenolic condensation. products, such as bakelite. Preferably a material is used which can be easily cut by high speed cutting tools.

According to my invention, a strip of the nonmetallic material is first attached firmly to the flexible support and then the fastener members are carved from the strip. Preferably the strip is notched to provide suitable attaching means before assembly to the strip and if desired, part of the carving operations required to form the interlocking portions may also be carried out on the strip before it is attached to the tape.

In the accompanying drawing, I have shown for purposes of illustration, one embodiment which my invention may assume in practice. In this drawing:

Fig. 1 illustrates one desirable form of the strip prior to attachment to the tape;

Fig; 2 illustrates the first carving operation after the strip is attached to the tape;

Figs. 3 and 4 show subsequent carving operations;

Fig. 5 shows the drilling operation; and

Fig. 6 is a plan view of a finished fastener of the separable interlocking type.

The strip illustrated is of generally rectangular cross-section which can be easily and cheaply manufactured. The strip comprises a solid portion 8 with a series of notches 9 dividing one side of the strip into a series'of teeth l0. By having the notches 9 in the strip prior to assembling it with the flexible support, the subsequent cutting operations can be carried out without injury to the flexible support. Each tooth is slotted as indicated at H longitudinally of the strip to receive the edge of a flexible support. When attached to the flexible support, herein a fabric tape [2, the solid portion 8 projects from the edge of the strip. In order to partially shape the projections before the elements are cut into blocks, carving operations illustrated in Figs. 2 and 3 are carried out. In Fig. Zvertical notches l3 are formed by a suitable cutting tool l4 and in Fig. 3 the inclined notches I5 are formed by suitable cutting tools l6 onopposite sides of the strip. The strip is next severed into blocks [1 by means of a rotary combination cutter l8 which carries a milling portion l9 adapted to cut the inclined face behind each projection and perform the final shaping operation on the projections. The strip is next'put into a suitable drilling machine which twists the fastener members out of the plane of the flexible support as indicated. in Fig. 5, so that the side of the fastener member to be drilled is out of the way of the adjacent members. The tapered recesses 20 can then be rapidly drilled in section by a drill 2|.

When two fastener stringers have ben completed according to-the method above described, they are assembled as shown in Fig. 6 with the projections 22 of the members on one side interlooking with the recesses 20 of the members on the opposite side. The fastener is opened and closed rapidly by means of a slider 23 which is actuated by a pull tab 24.

As a result of my invention it will be observed that a simple method has been devised for making fastener stringers whereby the many diificulties of attaching small individual members in accurately spaced relation on a flexible support are avoided.

While I have shown and described in this application one embodiment which my invention may assume in practice, it will be understood that this embodiment is merely for the purpose of illustration and description and that other forms may be devised within the scope of my invention as described in the appended claims.

What I claim as my invention is:

l. The method of making stringers for separable interlocking fasteners which comprises forming an elongated strip of material with a series of uniformly spaced teeth, said teeth having aligned slots to receive the edge of a flexible support and a portion projecting from the support, attaching said strip to a flexible support, and carving from said projecting portion a series of spaced elements each having a projection and a recess for interlocking with projections and recesses of cooperating elements.

2. The method defined in claim 1 wherein the carving of said projections comprises cutting angular exterior faces uniformly spaced apart, dividing the strip into individual blocks and finally shaping a projection on each block, and drilling a recess on the sides of said block opposite from the projections.

3. A strip for use in making stringers for separable interlocking fasteners comprising a solid bar of generally rectangular cross-section having notches along one side to provide a series of teeth for the attaching portions of the fastener members, and each of said teeth being slotted longitudinally of the strip for receiving the edge of a flexible support.

4. In the manufacture of separable interlocking fasteners, preparing a stringer with a series of uniformly spaced fastener member blanks attached to the edge of a tape, each blank consisting of a block-like member with means at one end secured to the tape and on the other end, a projection on one side extending toward the next adjacent member, twisting the fastener members successively out of the plane of the flexible support, and drilling in the face of each fastener member opposite the projection a recess adapted to receive a projection on a similar element.

5. In the manufacture of separable interlocking fasteners of the class described, the method which'comprises preparing a stringer with a series of uniformly spaced fastener member blanks attached to the edge of a tape, each blank having a portion securing it to the tape and a portion projecting from the edge of the tape, said projecting portion having an interlocking projection on one side, forming interlocking recesses on the side of each member opposite the projection by successively moving the fastener members so as to provide easy access to the side of the fastener member in which the recess is to be formed, and then forming such recess.

6. In the manufacture of separable interlocking fasteners of the class described, the process which comprises preparing a strip of material with spaced apart attaching portions along one side, attaching said portions to the edge of a tape stringer, then cutting out portions of said strip to form separate elements spaced apart on the tapes, and finally cutting a recess in each of the separate elements.

7. In the manufacture of separable interlocking fasteners, the process which comprises preparing a stringer with a series of uniformly spaced fastener member blanks attached to the edge of a tape, each blank consisting of a blocklike member with means at one end secured to the tape and on the other end, a projection on one side extending toward the next adjacent member, and drilling in the face of each fastener member opposite the projection a recess adapted to receive a projection on a similar element.

8. In the manufacture of separable interlocking fasteners, the process which comprises preparing a stringer with a series of blanks of nonmetallic material attached to a flexible support and then carving said blanks to provide a series of interlocking members adapted to interlock with similar members.

GIDEON SUNDBACK. 

